Utilization of waste rice straw for charcoal briquette production using three different binder

In the present work, rice straw was carbonized using a carbonization drum. However, carbonized rice straw has poor briquetting characteristics and requires a binder. Therefore, carbonized rice straw was mixed with three types of binders at three distinct levels and densified.

The physical properties, such as density value, ranged from 0.382 to 0.518 g/cm³, and Shatter resistance ranged from 67.566% to 91.621%. The water resistance test results ranged from 54.893% to 67.894%. The value range for high heating value is 24.049 MJ/kg to 28.639 MJ/Kg, and fixed carbon content is 20.36% to 37.07%.

The TGA curve showed the sample made using starch binder at a 20% level showed the best thermal stability. However, parameters such as the high cost of starch, its extraction, and being part of the human food chain make it comparatively unsuitable for commercial use, and taro can be an alternative binder. The emission test showed that the straw briquette showed lower emissions than the CO, NO_x, and SO_x emitted from burning chopped rice straws. The specific energy consumption was highest for paper binder briquettes, followed by taro binder and starch. The water boiling test showed that as the binder level increases, the burning increases.